Rome readies for as many as 1 million people to see 2 popes made saints in St. Peter's Square

Priests sing and dance in St. Peter's Square at the Vatican, Saturday, April 26, 2014. Pilgrims and faithful are gathering in Rome to attend Sunday's ceremony at the Vatican where Pope Francis will elevate in a solemn ceremony John XXIII and John Paul II to sainthood. (AP Photo/Emilio Morenatti)
(The Associated Press)

Polish President Bronislaw Komorowski, left, and Pope Francis look at each other on the occasion of their private audience at the Vatican, Saturday, April 26, 2014. Komorowski is in Rome to attend Sunday's canonization ceremony for John Paul II and John XXIII where Pope Francis will elevate the two popes to sainthood.(AP Photo/Vincenzo Pinto, Pool)
(The Associated Press)

A Polish nun holds a portrait of late Pope Pope John Paul II in front of St. Peter's Basilica at the Vatican, Saturday, April 26, 2014. Pilgrims and faithful are gathering in Rome to attend Sunday's ceremony at the Vatican in which Pope Francis will elevate in a solemn ceremony John XXIII and John Paul II to sainthood. (AP Photo/Emilio Morenatti)
(The Associated Press)

VATICAN CITY – By train, bus, car and on foot, pilgrims and tourists streamed into Rome on Saturday to participate in the ceremony in St. Peter's Square that will see two popes, John XXIII and John Paul II, be proclaimed saints.

Italy's interior minister says as many as 1 million people could be drawn to Rome for the extraordinary occurrence of two pontiffs being canonized at a Mass on Sunday where two living popes will be present. The Vatican has confirmed that retired Benedict XVI will help Pope Francis and dozens of cardinals celebrate the Mass outside St. Peter's Basilica.

The square will open to the faithful Sunday morning before dawn, and many people had spread out sleeping bags and mats in the area just outside the Vatican in hopes of securing prime viewing spots. The sound of hymns being sung in Italian, Polish, English and other languages could be heard Saturday in much of Rome as pilgrims made their way through the capital heading from buses and trains toward the Vatican. Some pilgrims set out weeks ago from Poland to make the journey by foot; others were arriving by horseback.

Tens of thousands of faithful, many of them young people, will pack several churches throughout Rome late Saturday for a prayer vigil.